In the related art, vehicle door lock devices are known which include a lock mechanism for setting an unlocked state where a latch mechanism on a vehicle door side can disengage from a striker on a vehicle body side, or a locked state where the latch mechanism cannot disengage from the striker. For example, JP 2011-26867A (Reference 1) discloses one of the vehicle door lock devices. This door lock device has a lever drive mechanism mounted thereon. The lever drive mechanism utilizes a structure in which an inside opening lever drives a lock operation lever from a locking position to an unlocking position during a door opening operation of an inside door handle. According to this configuration, the lever drive mechanism differentiates between a drive start timing of an opening link using the inside opening lever (first timing) and a drive start timing of the lock operation lever using the inside opening lever (second timing).
The lever drive mechanism will be more specifically described. According to a mechanism in which the second timing is set to be delayed than the first timing, a so-called “double-pulling mechanism”, the opening link is switched from the locking position to the unlocking position when the inside opening lever is rotatably operated from an initial position to a maximum operation position (also referred to as a “full position”) by the first door opening operation of the inside door handle. Therefore, the vehicle door is not unlocked by the first door opening operation of the inside door handle. Thereafter, during a process while the inside opening lever is rotatably operated again from the initial position to the maximum operation position by the second door opening operation of the inside door handle, the opening link previously located at the unlocking position engages with a lift lever of the latch mechanism. Accordingly, the latch mechanism is switched from a latched state to an unlatched state so that the vehicle door is unlocked. On the other hand, according to a mechanism in which the second timing is set to be earlier than the first timing, a so-called “one-motion mechanism”, when the inside door handle is used once for the door opening operation, an operation in which the opening link is switched from the locking position to the unlocking position and an operation in which the opening link engages with the lift lever of the latch mechanism are continuously performed so that the vehicle door is unlocked.
According to the door lock device having the above-described lever drive mechanism mounted thereon, in some cases, the lock operation lever is forcibly driven toward the locking position due to automatic lock control or manual control of the lock operation lever when the inside opening lever is located at the maximum operation position. This control can cause a possibility of the inside opening lever being prevented from properly returning to the initial position since the lock operation lever comes into contact with the inside opening lever. In this case, even after the inside door handle returns to the initial position by quitting the door opening operation, the inside opening lever cannot properly return to the initial position, and is kept at the maximum operation position. As a result, a flexible inside opening cable connected to the inside opening lever is bent, thereby causing a disadvantage that a cable end portion of the inside opening cable may drop out from an attachment hole of the inside opening lever or the cable end portion itself may buckle by being pressed against the inside opening lever.